A typical electrosurgical instrument includes a handle from which a small electrode extends, a cable extending from the handle to a source of high frequency electrical energy and one or more switches on the handle for selectively energizing the electrode. Contact of the energized electrode with living tissue results in concentrated localized heating enabling the instrument to be used for cutting, excising of unwanted tissue and coagulation of tissue to inhibit bleeding. Such instruments are well established as the preferred tool for many surgical procedures.
Use of an electrosurgical instrument typically causes a generation of smoke. This can obscure the surgeon's view of the tissue which is being operated on and can be disturbing to an un-anesthetized patient. Disagreeable odors may also be produced. Other fluids, such blood or applied saline solution, may also accumulate in the region where the electrode contacts the tissue.
Aspirating apparatus for removing such fluids from the operating site can greatly facilitate the surgeon's activities and provide a more comfortable environment for all persons who are present during use of an electrosurgical instrument.
Smoke and other fluids can be withdrawn from the vicinity of the electrode through a flexible tube which is connected to a vacuum canister. This complicates procedures and can be a distraction if the tube must be held and manipulated by the surgeon. It has been considered preferable to have another medical person operate the aspirator so that the surgeon may concentrate on the cutting or coagulation operations and have both hands available for necessary procedures. The need for additional personnel adversely affects the costs of electrosurgery.
Some prior electrosurgical instruments have been provided with a built-in internal passage connectable to a vacuum canister through tubing and which has one or more intake openings at the front end of the handle. Such instruments can avoid the need for additional personnel and enable more direct control of aspiration by the surgeon under some conditions but are not ideally suited for these purposes. The fluid intake opening is situated at the rear of the electrode which position is not always the most effective one for sucking in smoke or other fluids. A more forward intake location is preferable under many operating conditions. The optimum intake location is also influenced by variables such as the orientation in which the instrument is held, variable ambient air flows and the like. Built-in aspirators of the kind described above do not permit any adjustment to suit changing operating conditions.
Built-in aspirator ducts and fittings also increase the bulk and cost of manufacture of electrosurgical instruments. Current medical procedures favor the use, where possible, of low cost disposable instruments which can be discarded after a single use rather than instruments which must be sterilized for reuse.
The present invention is directed to overcoming one or more of the problems discussed above.